Thermochemical material removal



Jan. 27, 1953 E. MEINCKE 2,626,880

THERMOCHEMICAL MATERIAL REMOVAL Filed June 7. 1950 2 SHEETS-SHEET 1 W 5 Z4 1 Ill". 4

70 ,5 j lN VENTOR fl ATTORNEY f '2 guwm MIIINCKE M M E- MEINCKE THERMOCHEMICAL MATERIAL REMOVAL Jan. 27, 1953.

2 SI-IEETS-SI-IEET 2 Filed June '7, 1950 INVENTOR EDWARD MEINCKE ATTORNEY Patented Jan. 27, 1953 THERMOCHEMICAL MATERIAL REMOVAL Edward Meincke, Summit, N. J., assignor, by

mesne assignments, to Union Carbide and Carbon Corporation, a corporation of New York Application June 7, 1950, Serial No. 166,645

8 Claims.

This invention relates to thermochemical material removal, and more particularly to a method employing adjuvant powder in conjunction with oxy-acetylene material removal to facilitate the thermochemical reaction, and constitutes a continuation-in-part of my copending applications Serial No. 547,062 filed July 28, 1944 (now Patent 2,470,999), Serial No. 685,871, filed July 24, 1946, now abandoned, and Serial No. 94,663 filed May 21, 1949.

An important object of this invention is to provide an improved method for removing material thermochemically at a greatly increased rate and with increased efficiency. Other objects are toincrease the speed of the relative movement between an oxidizing gas stream and a body of material for a given quantity of material removed; and to increase the quantity of material removed during relative movement between an oxidizing gas stream and a body of material.

While the adjuvant powder may be projected satisfactorily in a single jet, slight variations in the method or apparatus may prevent this powder stream from striking the oxygen stream coincident with the line of out. It is therefore another object of the present invention to avoid this difficulty, and to introduce the powder so as to produce an envelope of burning powder surrounding at least the leading or lagging edge of the material removing oxygen stream.

Other objects are to provide even distribution of the adjuvant powder supply to several adjuvant powder jets, to cause the adjuvant powder to impinge against the oxygen stream at approximately the point of impact of the oxygen stream upon the material or between the point of impact and the nozzle, to project the adjuvant powder with sufficient velocity to blow the adjuvant powder through the preheat flame envelope and be preheated to its oxygen ignition temperature and then impinge against the stream of material removing oxygen.

According to the present invention, the method of thermochemical removal of material along a selected path on the surface of a body of such material, for example carbon steel, low alloy steel, or stainless steel, as by cutting, flame machining, or boring, comprises directing against a region of the surface of said body on said path Where the operation is to begin a preheat flame envelope, directing adjuvant powder from outside said preheat flame envelope through said preheat flame envelope to heat said powder to.

its oxygen ignition temperature and directing a stream of material removing oxygen from inside said preheat flame envelope to burn powder while the oxygen stream impels it toward said region, and to impinge upon said region contiguous to the preheat flame envelope and propagate the heat of combustion of said adjuvant powder to said body to supplement the surface heating effect of said flame and promote the metal-removing action of said stream of oxygen. The adjuvant powder can be introduced as a single stream or as several convergent streams on either the leading or lagging edge of the oxygen stream. When a plurality of powder streams are employed it is advantageous for them to converge together to a point in the path of flow of the stream of material-removing oxygen, and they preferably should be in a plane inclined to the preheat envelope and to the oxygen stream.

The adjuvant powder comprises a highly combustible material such as powdered iron, low carbon steel, cast iron or ferromanganese and mixtures of such metals with one another and other materials, such as manganese, and is suspended in a stream of air or other suitable gas.

The oxygen, preheat envelope and powder stream may be applied simultaneously, or in any desire dsequence. For quick starting, for example on carbon steel, the powder may be turned ofi as soon as the out is started, and the cut continued with oxygen and preheat flames alone. But for cutting stainless steel, for example, it is desirable to continue the powder stream, after the out has been started, and progress the stream of oxygen, preheat flame envelope, and adjuvant powder stream along the path of out while maintaining constant their relation to each other.

The present invention may employ a nozzle block having a bore for receiving a standard or conventional oxy-fuel blowpipe and a bore at one side thereof to form a powder chamber. From the bottom of the powder chamber a plurality of passages extend in converging relation to a point below the outlet of the oxy-fuel nozzle. The axes of these passages lie in a plane inclined to the oxygen passage of the nozzle, and terminate in orifices arranged in a row outside of the ring of preheat gas orifices of the nozzle. The powder chamber contains a baflie to provide even distribution of adjuvant powder to the several passages.

In another form of the invention a single stream of powder may be directed from a tube arranged alongside of a standard cutting nozzle and inclined forwardly and inwardly.

Further objects and features of novelty will be apparent as the following description pro- 3 ceeds, with reference to the accompanying drawings, in which:

Fig. 1 is a vertical section through one embodiment of apparatus according to the present invention, showing the same in operation for carrying out the method according to the present invention;

Fig. 2 is a section taken along the line 22 of Fig. 1;

Fig. 3 is a bottom plan view of the structure shown in Figs. 1 and 2;

Fig. 4 is a side elevational view showing another form of apparatus performing the method of the invention;

Fig. 5 is a bottom end view of the shown in Fig. 4; and

Fig. 6 is a side elevational view showing still another way for performing the method of the invention.

As shown in Fig. 1 the central material removing oxygen stream is surrounded by a plurality of oxy-iuel preheat flames F which form a preheat envelope surrounding the central oxygen stream 0, the gases being projected by an oxyfuel nozzle N. The adjuvant powder is introduced from a plurality of orificesD arranged outside of the preheat envelope and'inclined inwardly to project a plurality of adjuvant powder jets P obliquely through the preheat envelope in converging relationtoward the central oxygen stream 0. In the form shown the adjuvant powder orifices D are arranged in a row outside of the preheat envelope, and the adjuvant powder jets P lie in a plane inclined toward the preheat envelope and the oxygen stream, and the jets P converge and intersect the central oxygen stream 0 at a point A, which'is-be low the outlet of the nozzle N, and approximately at or slightly above the point of impact of the oxygen stream upon the work W.

The jets of adjuvant powder are blown through the preheat envelope and converge to form an envelope of burning powder surrounding at least the leading edge of the material removing oxygen stream. The powder streams P discharge from the powder orifices D with sufficient velocity to be blown through the preheat gas envelope, impinging against the oxygen stream 0, being preheated to the oxygen ignition temperature of the powder meanwhile.

In the form shown in the drawings, the adjuvant powder is supplied by a nozzle block it, which has a bore l2 to receive the oxy-fuel nozzle [NI At one side of the bore [2 the block [G is provided with a bore 14 to form a powder chamber.

As shown in Figs. 2 and 3, the block It! is drilled to form three converging passagesifi, l6, and [1, which have their axes in a plane inclined to the bore I2, the passages l and I! extending from the sides of the larger bore Id, and the passage IE extending from the center thereof. These three passages terminate in the orifices D at the bottom of the nozzle block. Id.

In order to cause the powder, as it exits from these three passages to be evenly distributed between the three, a baffle 23 is inserted in the bore It. The bafile 26 comprises a hollow tube closed at its lower end and provided with a plurality of small drilling outlets 22 spaced around the periphery near the bottom. The powder inlet tube 24 enters the upper or open end of the baffle 20, and a collar 23 centers the baffle within. the bore I4 to leave an annular space around the bafile. The inlet tube 24' is secured in the collar a pa a us 23, for example, by silver solder and the collar 23 is similarly secured in the bore [4.

The powder-laden gas stream from the inlet 24 passes into the baffle and through the outlets 22 filling the annular space around and under the bafile, and passes out through the three converging powder passages I5, [6 and H. The nozzle block In is secured to the nozzle N by a tapered split ring which engages'a similarly tapered section of the bore [2, and is contracted by the force of a cap screw 32. When thus secured in position, the nozzle block serves to locate the powder passages l5, l6 and l! in fixed relation to the oxygen stream 0, such that they converge toward a point below the mouth of the nozzle N along the axis of the oxygen stream.

Figs. 4 and'5 show an ordinary cutting nozzle N, of well-known construction, used in conjunction with a, separate adjuvant powder supply nozzle 35. The lower portion of the powder nozzle is inclined toward the nozzle N and has its outlet closely adjacent the lower end of the latter in position for discharging the stream of powder 3'! between two of the preheat orifices 39 at a sufficient velocity to penetrate the preheat flame envelope Al and impinge against the central oxygen stream 43. In Fig. 4 the powder nozzle 35 leads the cutting nozzle as the two nozzles progress in unison across the surface of the billet to form the kerf. Some gouging is apt to occur when starting a cut with the arrangement of Fig. 5 so that, when it is important to avoid gouging, the powder nozzle 35 is so positioned relative to the nozzle N as to follow or lag behind the latter as it traverses the surface, as shown clearly in Fig. 6.

I claim:

1. The method of thermochemical removal of material from a body of metal, which comprises directing against said metal body a preheat flame envelope, directing at least one separate stream of adjuvant powder consisting essentially of combustible ferrous metal particles inwardly and forwardly through said envelope in heating relation thereto from a point externally of said envelope, heating said metal particles substantially to ignition temperature during passage thereof through said flame envelope, and directing a stream of material removing oxygen against said body from Within said preheat envelope concurrent therewith and in converging relation with said adjuvant powder stream.

2. The method of thermochemical removal of material from a body of metal which comprises directing against said metal body a preheat flame envelope comprising a plurality of preheat flames, directing a stream of adjuvant powder consisting essentially of combustible metal particles inwardly and forwardly through said envelope in heating relation thereto and between a pair of said preheat flames from a point externally of said envelope, heating said metal particles substantially to ignition temperature during passage thereof through said flame envelope, and directing a stream of material removing oxygen against said body from within said preheat envelope concurrent therewith and in converging relation with said adjuvant powder stream;

3. The method of rapidly initiating the thermochemical removal of material along a selected path on the surface of a body of metal which comprises directing against a region of the surface of said metal body on such path a preheat envelope, directing an external stream of adjuvantpowder consisting essentially of combustible metal particles inwardly and forwardly through said preheat envelope in heating relation thereto to heat said powder to its oxygen ignition temperature, and directing a stream of material removing oxygen against said region from within said preheat envelope and in converging relation with said adjuvant powder stream to propagate the heat of combustion of said powder to said body.

4. A method of thermochemically removing metal from a. body of metal, which comprises directing against a surface of said body a preheating flame and a stream of metal removing oxygen while maintaining said flame and said stream contiguous at their regions of impingement against said surface; and concurrently directing at least one external stream of adjuvant powder consisting essentially of combustible metal particles forwardly and obliquely through said preheating flame in heating relation thereto and into said oxygen stream to first rapidly heat such powder to its ignition temperature and then burn such heated powder in said oxygen stream while the latter impels such burning powder toward said surface to supplement the surface heating efiect of said flame and promote the metal-removing action of said stream of oxygen.

5. In the art of thermochemically removing material from a body of metal and wherein both a preheating flame and an oxygen stream contiguous thereto are concurrently directed against a reaction zone on said body, the improvement which comprises the step of concurrently discharging adjuvant powder consisting essentially of combustible metal particles forwardly and obliquely through said preheating flame in heating relation thereto and into said oxygen stream as a plurality of powder streams, heating said metal particles substantially to ignition temperature during passage thereof through said preheating flame and then burning such heated particles in the leading edge of said oxygen stream while the latter impels the heated powder and burning particles toward said reaction zone, to supplement the heating eifect of said flame and to promote the material-removing action of said oxygen stream.

6. A method of progressively thermochemically removing metal from a body of metal which comprises concurrently directing against successive portions of said body both a preheating flame and an oxygen stream while maintaining the latter and said flame in contiguous relation adjacent their successive areas of impingement againstsaid body, and while both said preheat flame and said oxygen stream are being directed against successive portions of said body concurrently discharging adjuvant powder consisting essentially of combustible metal particles forwardly toward and obliquely through said preheating flame in heating relation thereto and into said oxygen stream as at least one continuously flowing powder stream converging with said oxygen stream, heating said metal particle ssubstantially to ignition temperature during passage thereof through said preheating flame and then burning such heated powder in said oxygen stream while the latter impels the heated and burning powder toward said areas to supplement the heating effect of said flame and to promote the metal-removing action of said oxygen stream.

'7. The method of thermochemically removing material from a body of such material which comprises directing a stream of material-removin oxygen against said body; directing at least one separate stream of adjuvant powder consisting essentially of combustible metal particles in downwardly converging relation with said oxygen stream; and concurrently directing against said body preheat flame between said stream of adjuvant powder and said oxygen stream in heating relation to said adjuvant powder stream, and heating said metal particles therewith substantially to ignition temperature during passage thereof to said oxygen stream.

8. The method in accordance with claim '7 wherein said adjuvant powder is directed only in a single stream.

EDWARD ME-INCKE.

REFERENCES CITED The following references are of record in the flle of this patent:

641/26 Australia Feb. 19, 1926 

1. THE METHOD OF THERMOCHEMICAL REMOVAL OF MATERIAL FROM A BODY OF METAL, WHICH COMPRISES DIRECTING AGAINST SAID METAL BODY A PREHEAT FLAME ENVELOPE, DIRECTING AT LEAST ONE SEPARATE STREAM OF ADJUVANT POWDER CONSISTING ESSENTIALLY OF COMBUSTIBLE FERROUS METAL PARTICLES INWARDLY AND FORWARDLY THROUGH SAID ENVELOPE IN HEATING RELATION THERETO FROM A POINT EXTERNALLY OF SAID ENVELOPE, HEATING SAID METAL PARTICLES SUBSTANTIALLY TO IGNITION TEMPERATURE DURING PASSAGE THEREOF THROUGH SAID FLAME ENVELOPE, AND DIRECTING A STREAM OF MATERIAL REMOVING OXYGEN AGAINST SAID BODY FROM WITHIN SAID PREHEATED ENVELOPE CONCURRENT THEREWITH AND IN CONVERGING RELATION WITH SAID ADJUVANT POWDER STREAM. 